Office



Patented July 12, I898.

U. S. G. BRUBST.

SAFETY .ENVELUP.

(Application filed July 12, 1897.)

(N0 Modeli) Fig. E

Nrrnn STATES PATENT: Fries.

ULYSSES SIMPSON GRANT BROBST, OF COLUMBUS, OHIO, ASSI GNOR OF ONE-THIRD TO CHARLES BENTZ, OF SAME PLACE.

SAFETY-ENVE LO P.

SPECIFICATION forming part of Letters Patent No. 607,336, dated July 12, 1898.

Application filed July 12 1897. Serial No, 644,306. (No model.)

To all whom it may concern.-

Be itknown that I, ULYSSES SIMPSON GRANT BROBST, of Columbus, in the county of Franklin and State of Ohio, have invented certain new and useful Improvements in Safety-Envelops and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to an improved safety-envelop, and has for its object to produce a device of this character which cannot be surreptitiously opened without detection.

To the accomplishment of this object my invention consists in providing a sealing-flap secured at its opposite ends to the opposite extremities of the envelop adjacent to the open edge and having a serrated flap which extends upon opposite sides of the envelop and is secured thereto in a peculiar manner which makes it impossible for the flap to be opened without destroying the integrity of the same or without so distorting the flap as to make it absolutely impossible for it to be resecured in a manner to avoid detection. Certain other structural peculiarities subordinate to the distinctive feature mentioned will hereinafter be more fully pointed out.

Referring to the drawings, Figure 1 is a front view of my envelop. Fig. 2 is a rear view of the same. Fig. 3 is a front elevation of the envelop unsealed. Fig. dis a transverse sectional view. Fig. 5 is a view of the blank from which the envelop is made. Fig. 6 is a detail View of the lining detached.

Referring to the numerals on the drawings, 1 indicates the body part or front of my envelop provided along one side with a sealingflap 2, having its edge serrated, and along its opposite edge with a back flap 3 of greater width than the width of the body part and of somewhat less length than the length of said body part, a crease being formed adjacent to its free edge and the end edges of the end flap beyond the crease converging in the manner illustrated and for a purpose which will hereinafter be made apparent. Comparatively short end flaps at extend from the ends of the body part and are designed to project when the envelop is complete just under the adjacent edges of the back flap.

6 indicates a preferably scalloped slit in the front 1, substantially parallel with the edge adjacent to the sealing-flap, and having angular extensions 8, extending from the upper edge of the envelop to the ends of the parallel slit, the extremities of the angular extensions or slits terminating a slight distance from either end of the envelop. By this construction it will be seen that a sealing-flap is formed which is secured to the envelop by a narrow strip at either end and which projects upon opposite sides of the envelop and is provided with serrated edges designed normally to aline with the adjacent correlatively-serrated edge along the slit in the front.

9 indicates a lining which consists, preferably, of a sheet of paper folded upon itself and designed to be placed within the envelop and to completely correspond therewith in size. As shown in the drawings, the end of the back flap, which has been described as having oppositely-inclined end edges, is folded over the upper edge of the lining and is secured by the sealing-flap extending along the front, and I shall therefore call this upper folded edge the inner sealing-flap 10. Ordinarily the portion of the sealing-flap extending upon the back of the envelop is opened or unsealed, and the sealing-flap extending upon the front of the envelop is secured by some adhesive material to the lining. It will now be apparent that the letter or other missive may be inserted into the envelop between the layers of the lining, and that the inner sealing-flap may then be folded over the upper edge of said lining beneath the sealing-flap above the serrated slit, and the sealing-flap proper or that portion which extends upon the back is then folded down upon the envelop and sealed in the ordinary manner, it being of course understood that the inner flap 10 is folded into position and sealed prior to the front flap.

The stamp 11 is preferably placed over one of the slit extensions and the device is ready for mailing. If desired, the inner sealingflap 10 maybe provided with adhesive material upon one or both sides, so as to cause it to adhere to the lining or to the front sealingflap, or to both. Supposing now that a surreptitious entry of the envelop is attempted, the sealing-flap will in most cases be steamed to soften the adhesive material along the serrated edge. This operation will serve to distort the serrations, and if the gum is not entirely loosened will cause one or more of the fragile points to be detached, thus leaving an evidence of the attempt at unsealing. If, however, this operation is accomplished, it will be seen that the inside sealing-flap must now be turned out and that in so doing the finger must be inserted into the envelop or, rather, between the front sealing-flap and the inner sealing-flap to be detached. This operation will serve to detach the front sealingfiap, and after the serrations have once been disalined it will be found impossible to bring them back to their proper relations, and, furthermore, this attempt to release the inside sealing-flap will probably be accompanied by the tearing of the thin strip of material which connects the sealing-flap proper with the material of the envelop,and anyattempt to steam the front flap will cause its distortion and will not only in this manner evidence the surreptitious entry, but will make the material so fragile that the slightest attempt to. thereafter release the inside sealing-flap will i be accompanied by the tearing of part of the envelop.

From the foregoing it will be noted that I have devised an envelop of novel construction which renders surreptitious examination of the contents impossible without detection, and while the embodiment of my invention illustrated and described appears at this time to be preferable, I do not desire to limit myself to the structural details, but reserve the right to change, modify, or vary such details within the scope of my invention.

Having thus described my invention, what I'claim as new, and desire to secure by Letters Patent, is-

1. An envelop provided with an inner and an outer sealing-flap folded in opposite directions, the said envelop having a slit for the passage of the inner flap, substantially as specified.

2. An envelop provided with a slit in its front, with an inner sealing-flap designed to be secured to the inside of the envelop above said slit, and with an outer sealing-flap, substantially as specified.

3. An envelop having a slit in its front, extending parallel to one edge and having extensions extending from the opposite ends of the slit to the edge of the envelop, an inner sealing-flap adapted to be secured to the inside of the envelop above the lower edge of said slit, and an outer sealing-flap designed to be secured to the back of the envelop, substantially as specified.

4. An envelop provided with a lining and with an inside sealing-flap designed to be folded over the upper open edge of the lining and to be inserted between the lining and the front of the envelop, with a serrated slit extending parallel to the upper edge of the envelop and provided with terminal extensions extending from the terminals of the serrated slit to the upper edge of said envelop, and with a sealing-flap designed to be folded down upon the back of the envelop, substantially as specified.

In testimony whereof I have signed this specification in the presence of two subscribing witnesses.

- ULYSSES SIMPSON GRANT liIiOBS'l.

Witnesses:

CHAS. K. RICHARDS, GEORGE W. Rnonns. 

